在试图开发android应用程序时获取java.lang.ClassCastException

Question

我有这个异常“java.lang.ClassCastException：android.app.Application无法转换为com.utility.TablePlussAndroid” 我不明白为什么.. 。非常感谢您的帮助

package com.tableplustablet; 
private com.utility.TablePlusAndroid session; 

public class LoginActivity extends Activity { 

    // ... 

    // get session from Application       
    session = (TablePlusAndroid) this.getApplication(); // <--EXCEPTION 
    session.setUserKey(userKey); 
} 

// ------------------------------------------------------------- 

package com.utility; 
import android.app.Application; 

//Save User Data in application's context 
public class TablePlusAndroid extends Application{ 
private Long userKey; 
private String userName; 
private Long currentTableKey; 

    public Long getCurrentTableKey() { 
     return currentTableKey; 
} 

    public void setCurrentTableKey(Long currentTableKey) { 
     this.currentTableKey = currentTableKey; 
    } 
    public Long getUserKey(){ return userKey;} 
    public void setUserKey(Long key){ userKey=key;} 
    public String getUserName() { return userName; } 
    public void setUserName(String userName) { this.userName = userName; } 
} 

Answer 1

您需要在AndroidManifest.xml文件中使用您的应用程序类。

它应该是这样的：

<application android:name="application.package.and.class"> 
    <activity .... /> 
</application>